Field effect transistors (FETs) can be used in power switching circuits, such as DC-DC converters. In these and other applications, high power density and energy efficiency are desirable. Power switching circuit efficiency generally decreases with increasing FET operating temperature. Switching signals can be modified according to FET temperature to facilitate efficient operation, if the FET temperature can be accurately determined. A temperature diode in a driver integrated circuit (IC) may give an incorrect temperature reading due to a temperature difference between the driver IC and FETs in a different semiconductor die or dies. Different packaging configurations of FET dies and controller or driver dies can lead to different temperature inaccuracies and inhibit energy efficiency for power circuits and the like.